1. Field of the Invention
This invention relates generally to vascular occlusion devices and particularly to a vascular occlusion device which is used to reduce the size of an aneurysm.
2. Description of the Prior Art
A number of techniques have been developed for the treatment of aneurysms. Initially, aneurysms were treated by invasive surgical methods. A physician would need to surgically remove the aneurysm from the parent vessel. Such procedures prove more challenging and carry a greater risk of impairment due to collateral damage when the aneurysm occurs in sensitive areas of the body, such as the brain.
Less invasive techniques have been developed. These techniques involve filling the aneurysm with material to prevent the aneurysm from growing in size. The aneurysm may be filled with a variety of structures, such as coils or balloons. Frequently, the structures used to fill an aneurysm are coated with a thrombogenic material, such as in U.S. Pat. No. 4,638,803 to Rand.
Polymers have also been used to fill aneurysms. For example, U.S. Pat. No. 5,041,090 to Scheglov, et al., discloses an aneurysm occluding device. A pair of balloons, one disposed within the other, is placed within an aneurysm. The inner balloon is expanded to force the outer balloon to contact the wall of the aneurysm. The inner balloon is filled with a polymer and the outer balloon is filled with an adhesive which flows through perforations in the outer balloon. The aneurysm adheres to the outer balloon and the layer of adhesive forms a bond between the outer balloon and the inner balloon.
Such a procedure requires the use of a detachable balloon. Some examples of detachable balloon designs can be found in U.S. Pat. No. 4,517,979 to Pecenka, U.S. Pat. No. 4,545,367 to Tucci, and U.S. Pat. No. 4,085,757 to Pevsner. In each case, a single balloon has a sealing valve assembly which seals the balloon when the catheter is removed.
The filling material, whether coils or polymers, are introduced into the body using catheters. The catheters are navigated through blood vessels to the site of the aneurysm. Such endovascular techniques are often preferred to the traditional invasive procedures due to reduced post-operative complications and recovery time.
Filling an aneurysm is not always an adequate solution, however. In some cases, the size of the aneurysm interferes with the surrounding tissue or other blood vessels. In these cases, filling the aneurysm does not reduce the xe2x80x9cmass effectxe2x80x9d caused by the aneurysm. Therefore, the prior art does not always produce adequate results.
In accordance with the present invention, there is an endovascular aneurysm occlusion device comprising a catheter. The catheter includes an outer tubular member having a proximal end, a distal end, and a lumen extending therethrough. The catheter also includes an inner tubular member having a proximal end, a distal end, and a lumen extending therethrough. The inner tubular member is coaxially disposed within the lumen of the outer tubular member.
The occlusion device also includes a balloon assembly having an outer balloon having an outer wall defining an interior region and an inner balloon having an outer wall defining an interior region. The inner balloon is disposed within the interior region of the outer balloon.
The balloon assembly also includes a valve assembly. The valve assembly extends through the wall of the outer balloon and an adjacent,portion of the wall of the inner balloon. The valve assembly has a passageway therethrough and a valve means disposed in the passageway. The distal end of the outer and inner tubular members of the catheter extending into the passageway, and the valve means is operative to permit the passage of the catheter through the valve assembly but preventing the flow of fluid through said valve assembly when the catheter is withdrawn from said valve assembly.
The occlusion device also includes a hub having a first lumen and a second lumen. Each lumen extends through the hub connector. The hub is mounted to the proximal end of the outer tubular member and the proximal end of the inner tubular member such that the first lumen of the hub is in fluid communication with the lumen of the outer tubular member and the second lumen of the hub is in fluid communication with the lumen of the inner tubular member.
In accordance with another aspect of the present invention, the outer balloon is formed of a porous material.
In accordance with still another aspect of the present invention, there is a method for occluding an aneurysm by the use of an occlusion device comprising a balloon assembly which includes an outer balloon, an inner balloon, and a valve assembly. The outer balloon is formed from a porous material and the inner balloon is disposed within the outer balloon. The valve assembly extends through a wall of the inner balloon and an adjacent wall of the outer balloon. A catheter has its distal end removably disposed within the valve assembly. The method comprises the steps of: positioning the balloon assembly within an aneurysm; inflating the inner balloon such that the inner balloon makes contact with the outer balloon to thereby force the outer balloon into contact with the aneurysm; introducing an adhesive material into a region between the inner balloon and the outer balloon thereby causing the inner balloon to become bonded to the outer balloon; perfusing the adhesive material through the porous material of the outer balloon thereby causing the outer balloon to become bonded to the aneurysm; deflating the inner balloon thereby causing the outer balloon to contract which, in turn, reduces the size of the aneurysm; and, detaching the catheter from the balloon assembly thereby causing the valve assembly to close and thereby causing the inner balloon to remain in a deflated state.